flex远程下载文件实例(进阶版)

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">

    <mx:Script>
   <![CDATA[
    private var downloadURL:URLRequest;
    private var netFile:FileReference;
  
    public function download(netFileURL:String):void{
     downloadURL = new URLRequest(netFileURL);
     netFile = new FileReference();
     configureListeners(netFile);
     netFile.download(downloadURL);
    }
  
    private function configureListeners(dispatcher:IEventDispatcher):void{
     dispatcher.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
     dispatcher.addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);    //当由于安全错误导致下载失败时调度
     dispatcher.addEventListener(Event.SELECT, selectHandler);    //当用户从对话框中选择要下载的文件时调度
     dispatcher.addEventListener(Event.OPEN, openHandler);    // 当下载操作开始时调度
     dispatcher.addEventListener(ProgressEvent.PROGRESS, progressHandler);    //在文件下载操作期间进行定期调度
     dispatcher.addEventListener(Event.CANCEL, cancelHandler);     //当用户取消对话框时调度
     dispatcher.addEventListener(Event.COMPLETE, completeHandler);    //当文件下载操作成功完成时调度
    }
  
    private function selectHandler(event:Event):void {
     var file:FileReference = FileReference(event.target);
     trace("文件网络地址：" + downloadURL.url);
    }
  
    private function openHandler(event:Event):void {
       trace("openHandler: " + event);
    }
  
    private function progressHandler(event:ProgressEvent):void {
       var file:FileReference = FileReference(event.target);
       trace("文件本地化后的名称：" + file.name);
       trace("已下载字节数：" + event.bytesLoaded);
       trace("文件总字节数：" + event.bytesTotal);
       trace("文件下载到本地的日期：" + file.creationDate);    //Fri Jan 15 09:15:29 GMT+0800 2010
       trace("文件格式：" + file.type);
       trace("到本地时的文件大小：" + file.size);
    }
  
    private function cancelHandler(event:Event):void{
       trace("cancelHandler: " + event);
    }
  
    private function completeHandler(event:Event):void {
       trace("completeHandler: " + event);
    }
  
    private function ioErrorHandler(event:IOErrorEvent):void {
       trace("错误信息: " + event);
    }
  
    private function securityErrorHandler(event:SecurityErrorEvent):void {
       trace("securityErrorHandler: " + event);
    }
  
   ]]>
</mx:Script>

<mx:Button x="300" y="50" label="远程文件下载"
click="download('http://www.google.cn/intl/zh-CN/images/logo_cn.gif');"/>

</mx:Application>